AQA Combined Science: Chemistry Paper 1 HIGHER

What are all substances made out of?

Atoms

One type of atoms joined together

Elements

Two or more elements chemically bonded

Compounds

Two or more elements not chemically bonded

Mixtures

Why do scientists use chemical formulae?

To find out how many compounds are in each element

How are compounds separated?

Electrolysis

What are the reactants?

Substances that are reacted

What are the products?

The new substances that are formed

What is filtration?

Separate soluble solutions from insoluble solutions

What is Crystallization?

Obtaining a soluble from a solution

What is Simple Distillation?

Obtaining a solvent from solution

What is Fractional Distillation?

Separating mixtures with different boiling points

What is Chromatography?

Separating the different soluble, coloured components of a mixture

What is the 'Plum Pudding Model'?

JJ Thomson believes electrons were surrounded by a sea of positive charge

How did Rutherford improve the arrangement of the atom?

He created a nucleus, containing protons and neutrons

How did Bohr improve the arrangement of the atom?

He created the shells which the electrons would orbit around

What was the relative mass of the proton?

1

What was the relative mass of the neutron?

1

What was the relative mass of the electron?

1/1840

What was the relative charge of the proton?

+1

What was the relative charge of the electron?

-1

What was the relative charge of the neutron?

0

What is an isotope?

An element with the same amount of protons and electrons but different number of neutrons

What is the electron configuration?

Shows how electrons are arranged around the nucleus in shells.

How do atoms become ions?

They gain or lose electrons

What is a negative ion?

An atom that has gained electrons

What is a positive ion?

An atom that has lost electrons

Who was John Newlands?

He tried to put the periodic table together but noticed there were gaps missing

Who was Dimitri Mendeleev?

He created the periodic table, leaving gaps for elements that were yet to be discovered

What are Group 0 also know as?

Noble gases

Why are noble gases unreactive?

Because they have a full outer shell

What are the Group 1 elements also known as?

Alkali metals

Why are alkali metals stored in oil?

So they don't react with the oxygen in the air

What happens when an alkali metal reacts with water?

A metal hydroxide is formed and hydrogen is given off

Why do alkali metals float?

They have a low density

What are Group 7 elements called?

Halogens

What are the 3 states of matter?

Solid, Liquid, Gas

What does (s) stand for?

Solid

What does (l) stand for?

Liquid

What does (g) stand for?

Gas

What does (aq) stand for?

Aqueous (dissolved in water)

What are the 3 types of strong bonds?

Ionic bonds, covelent bonds, metallic bonds

When are ionic bonds formed?

When ions lose and gain their electrons to another atom, or vise versa

What are the properties of ionic compounds?

High melting and boiling points, do not conduct electricity when solid or molten

What are covelent bonds?

When atoms share a pair of electrons

What are metallic bonds?

The attraction between positive ions and the delocalised negatively charged electrons

What does delocalised mean?

Not bond to one atom

What are the properties of metals?

It is ductile, malluable, good conductivity

What are alloys?

Mixtures that contain a metal and at least one other element

What is the conservation of mass?

The total mass of the product is equal to the total mass of the reactants

What are half equations used for?

To show what happens to one reactant in a chemical reaction, with electrons

How do you calculate the relative formula mass?

Add all of the elements' atomic masses together (if there is more than one, multiple to atomic mass of that element by the amount shown)

How do you work out the number of particles in an substance (mol)

mass of substance (g) / formula mass (g/mol)

What is oxidation?

A substance gaining oxygen or the loss of electrons

What is reduction?

A substance that loses oxygen or the gain of electrons

What number/ colour is acidic?

1 / Red

What number/ colour is neutral?

7 / Green

What number/ colour is alkaline?

14 / Purple

What is electrolysis?

The use of electrical currents used to break down compounds containing ions into their constituent elements

What are the electrodes made out of?

Usually carbon

What is the anode?

The positive electrode

What is the cathode?

The negative electrode

What is an exothermic reaction?

When heat is given out

What is an endothermic reaction?

When heat is taken in

How do you calculate the energy transfer in a reaction?

Add up the shown bonds

What is the equation for the rate of reaction?

amount of reactant used or product formed / time taken

How do you calculate the concentration?

Amount of mol /volume of reaction mixture

How do you measure the amount of gas formed?

Use a gas syringe

What is the activation energy?

The minimum energy required to cause a reaction

What are the 4 main factors that increase the rate of reaction?

Concentration, tempreture, surface area, catalysts

What is an equilibrium?

When the products and the reactants are balanced in an equation

What in the Le Chantelier's Principle?

If equilibrium changes in conditions, that the system shifts to resist the change